CN113007048B

CN113007048B - Power generation device based on human knee joint and ankle joint drive

Info

Publication number: CN113007048B
Application number: CN202110279987.5A
Authority: CN
Inventors: 陈兵; 郑成旺; 王兵; 訾斌
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2021-03-16
Filing date: 2021-03-16
Publication date: 2022-05-17
Anticipated expiration: 2041-03-16
Also published as: CN113007048A

Abstract

The invention relates to a power generation device based on human knee joint and ankle joint driving, and belongs to the technical field of human power generation devices. Comprises a power generation mechanism, a knee rope, an ankle rope, a thigh support, a shank support connecting rod and an ankle connecting rod; the power generation mechanism comprises a power generator, a worm and gear mechanism, a first input mechanism, a second input mechanism and a transition transmission mechanism; the transition transmission mechanism comprises a pair of gears and a transition gear; the transition transmission mechanism is respectively connected with the first input mechanism and the second input mechanism in a transmission way, and a worm shaft of the worm gear mechanism is connected with an input shaft of the generator; the power generation mechanism is connected with the shank bracket through a shank bracket connecting rod; one end of the knee rope is connected with the thigh bracket, and the other end of the knee rope is wound on a first pulley of the first input mechanism; one end of the ankle rope is wound on the second pulley, and the other end of the ankle rope is connected with the ankle connecting rod. The invention collects the negative work generated by the knee and ankle joints when the human body walks, reduces the metabolism consumption and realizes that the human body can obtain electric energy at any time when walking.

Description

Power generation device based on human knee joint and ankle joint drive

Technical Field

The invention belongs to the technical field of human body power generation devices, and particularly relates to a power generation device based on human body knee and ankle joint driving and a control method thereof.

Technical Field

With the continuous progress of society, various wearable electronic devices, exoskeletons, artificial limbs and the like are rapidly developed, and the continuous supply of electric energy of the devices is a problem which troubles people. When a user needs to continuously work for a long time or carry out outdoor work, the user cannot be charged in time, and for soldiers who carry out outdoor tasks, continuous electric energy supply is an important guarantee for the soldiers to smoothly complete the tasks; in order to avoid influencing the flexibility of field activities of users, the volume and the weight of a power supply carried by the users are reduced as much as possible, but the existing battery has low energy density, long charging time and short service life and cannot meet the requirements.

Researchers have therefore sought sustainable energy supplies for portable devices to address these issues. Research shows that the fat of the human body stores abundant energy, the energy density in the fat far exceeds that of a battery, and the energy stored in the fat of a person with medium size is about equivalent to that of a battery of 1000kg, so that the human body is a huge energy bank, and collectors based on energy obtained from the movement of the human body are gradually used for supplying power to portable equipment. The knee joint approximately generates 67W power to assist walking when a human body normally walks, wherein more than half of the power executes negative work, and the generated electric energy can completely meet the electric energy requirement of the portable equipment by collecting the power generated when the human body walks.

At present, domestic devices for realizing human body power generation mainly collect the motion of joints in two directions and collect the positive work and the negative work of a human body at the same time. A knee joint power generation device adopts a ball screw structure, the rotary motion of a knee joint is converted into the linear motion of a screw nut through a pull rope, and then the linear motion is converted into the high-speed rotary motion of the ball screw, and finally the power generation function of a generator is realized; on the other hand, the generator needs to rotate forwards and backwards continuously during bidirectional acquisition, and the inertia of the rotor of the generator easily impacts the human body to influence the gait during normal walking. Therefore, a new human body power generation device needs to be researched, which can only collect the negative work generated by the human body when the human body normally walks, and can not affect the normal gait of the human body and increase the consumption of the metabolism of the human body.

Disclosure of Invention

The invention provides a power generation device based on human knee joint and ankle joint driving, aiming at realizing the functions of collecting negative work generated at a knee and ankle joint when a human body walks, assisting the movement of the knee and ankle joint, reducing the consumption of metabolism when the human body walks, efficiently generating power and the like.

The power generation device based on the drive of the knee joint and the ankle joint of the human body comprises a power generation mechanism 3, a knee rope 1, an ankle rope 2, a thigh support 25, a shank support 26, a shank support connecting rod 27 and an ankle connecting rod 28;

the power generation mechanism 3 comprises a power generator 23, a worm and gear mechanism, a first input mechanism, a second input mechanism and a transition transmission mechanism; the transition transmission mechanism comprises a pair of gears and a transition gear 16; the transition transmission mechanism is respectively connected with the first input mechanism and the second input mechanism in a transmission way, and a worm shaft of the worm gear mechanism is connected with an input shaft of a generator 23 through a coupler 22;

the power generation mechanism 3 is connected with a lower leg bracket 26 through a lower leg bracket connecting rod 27;

one end of the knee rope 1 is fixedly connected with a thigh support 25, and the other end of the knee rope 1 is fixedly wound on a first pulley 7 of the first input mechanism;

one end of the ankle rope 2 is fixedly wound on the second pulley 12 of the second input mechanism, and the other end of the ankle rope 2 is fixedly connected with an ankle connecting rod 28;

in use, the thigh support 25 is secured to a person's thigh, the lower leg support 26 is secured to a person's lower leg, and the ankle link 28 is secured to the heel of a person's foot.

The further concrete technical scheme is as follows:

the first input mechanism of the power generation mechanism 3 comprises a first input shaft 4, a first input gear 5, a ratchet wheel and pawl mechanism 6, a first pulley 7 and a first torsion spring 8; the first input gear 5, the ratchet wheel 61 of the ratchet wheel and pawl mechanism 6, the first pulley 7 and the first torsion spring 8 are sequentially sleeved on the first input shaft 4;

the second input mechanism comprises a second input shaft 9, a second input gear 10, a one-way transmission mechanism 11, a second pulley 12, a linear compression spring 14 and a second torsion spring 13, and the one-way transmission mechanism 11 comprises a toothed disc 111 and a toothed disc 112; the second input gear 10, the toothed disc 111 and the toothed disc 112 of the unidirectional transmission mechanism 11, the second pulley 12, the linear compression spring 14 and the inner ring of the second torsion spring 13 are sequentially sleeved on the second input shaft 9.

A pair of gears of the transition transmission mechanism is a driving gear 17 and a driven gear 19; the driven gear 19 and the worm gear 20 are coaxially and fixedly arranged on the second transmission shaft 18, and the driving gear 17 and the transition gear 16 are coaxially and fixedly arranged on the first transmission shaft 15; the transition gear 16 meshes with the first input gear 5 and the second input gear 10, respectively.

The ratchet-pawl mechanism 6 comprises a ratchet wheel 61, a pair of pawls 62, a pair of compression torsion springs 63 and a housing 64; the shell 64 is an annular shell with a flange, the axial side face of the shell 64 is fixedly connected with the axial end face of the adjacent first pulley 7, the pair of pawls 62 are symmetrically and movably arranged in the shell 64, one end of the compression torsion spring 63 is fixedly connected with the pawls 62, and the other end of the compression torsion spring 63 is fixedly connected with the inner wall of the shell 64.

The first torsion spring 8 comprises an inner ring 81 and an outer ring 82 which are concentric, and eight flexible bodies 83 are uniformly distributed between the inner ring 81 and the outer ring 82. Outer ring buckles 84 are uniformly distributed on the outer ring 82 on one axial side surface of the first torsion spring 8, and inner ring buckles 85 are uniformly distributed on the inner ring 81 on the other axial side surface of the first torsion spring 8; the first torsion spring 8 is fixedly connected to the housing 24 of the power generation mechanism 3 by an inner ring clip 85, and is fixedly connected to the axial end face of the adjacent first pulley 7 by an outer ring clip 84.

Each flexible body 83 is formed by connecting more than one S-bend in sequence.

The fluted disc 112 is fixedly connected to one side end face of the second pulley 12 in an embedded manner; four arc-shaped teeth are uniformly distributed on the axial end face of one side of the toothed disc 111, the toothed disc 112 comprises an outer ring, an inner ring and a plurality of toothed blades, and the toothed blades are uniformly distributed and connected between the outer ring and the inner ring; the arc teeth of the tooth-shaped disc 111 and the single tooth-shaped blade of the tooth-shaped disc 112 have the same structure, when the tooth-shaped disc 111 is meshed with the tooth-shaped disc 112, the four arc teeth on the tooth-shaped disc 111 are just embedded into the corresponding tooth-shaped blades on the tooth-shaped disc 112, one end of the linear compression spring 14 is fixedly connected with the shell 24 of the power generation mechanism 3, and the other end of the linear compression spring is fixed on the other end surface of the second pulley 12; the elastic force of the linear compression spring 14 presses the second pulley 12 to maintain the toothed disc 112 and the toothed disc 111 in a meshed state.

Compared with the prior art, the beneficial technical effects of the invention are embodied in the following aspects:

the invention is provided with two input mechanisms, each input mechanism is provided with a one-way transmission mechanism, when a human body normally walks, the power generation device can effectively collect negative functions generated by the human body when the knee joint makes stretching movement and the ankle joint makes dorsiflexion movement, reduces the loss of metabolism of the human body, converts the biological energy of the human body into the electric energy of the power generator, and realizes that the human body can obtain the electric energy anytime and anywhere when the human body normally walks. According to the invention, the two input mechanisms are respectively provided with the torsion springs which are respectively used for storing negative work collected from the knee joint and the ankle joint of a human body and keeping the knee rope and the ankle rope tensioned, the elastic potential energy of the torsion springs can provide positive work for plantar flexion of the ankle joint when released in the later period of support, and meanwhile, the designed torsion springs can realize the effect of assisting the swinging and deceleration of the shank in the later period of swinging, so that the power generation device can reduce the positive work requirement of the human body when the human body walks through the recovered energy, thereby reducing the metabolism of the human body and being beneficial to relieving the fatigue feeling of the human body. The invention is provided with the thigh support, the shank support and the shank support connecting rod, is convenient to wear, has compact structure, is not limited by external environmental conditions, is energy-saving and environment-friendly, is suitable for soldier field training or long-time field working users, and does not influence the normal gait of the users.

The invention is used for recovering the negative work generated when the knee joint is stretched in the swing stage and the ankle joint is dorsiflexed in the standing stage during the movement of the human body, and realizes the functions of generating electricity and assisting walking. Biomechanical analysis shows that the knee joint and the ankle joint generate the most negative work, only the knee joint can generate 67W of power, the negative work percentage is up to 90%, the peak efficiency of the muscle for converting the metabolic energy into the positive work is 25%, the peak efficiency of the muscle for executing the negative work is 120%, and therefore, the metabolic consumption can be obviously reduced by only collecting the negative work at the knee and the ankle joint.

According to the biomechanical analysis, the dorsiflexion angle of the ankle joint in the standing stage is about 10 degrees, and the dorsiflexion angle of the ankle joint in the swinging stage is only about 3 degrees, so that the positive work generated in the dorsiflexion of the ankle joint in the swinging stage can be avoided by adjusting the length of the ankle rope. The first input mechanism and the second input mechanism are respectively provided with the ratchet wheel and pawl mechanism and the one-way transmission mechanism which can only realize one-way transmission, so that the mutual influence of the movement of the knee joint and the ankle joint is avoided, and the reaction torque cannot be brought to the joint.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention in use.

Fig. 2 is a schematic structural view of the power generation mechanism.

Fig. 3 is a top view of fig. 2.

Fig. 4 is a schematic diagram of the structure of the transition transmission mechanism.

Fig. 5 is a schematic view of the first input mechanism.

Fig. 6 is a sectional view of the first input mechanism.

Fig. 7 is a cross-sectional view of the ratchet-pawl mechanism.

Fig. 8a is a front view of the first torsion spring.

Fig. 8b is a rear view of the first torsion spring.

Fig. 9 is a schematic structural view of the second input mechanism.

Fig. 10 is a structural schematic view of the second input mechanism with the second torsion spring removed.

Fig. 11 is a sectional view of the second input mechanism.

FIG. 12 is a partial cross-sectional view of a toothed disc, a fluted disc and a second pulley assembly.

Fig. 13 is a perspective view of a toothed disc.

FIG. 14 is a perspective view of a spline disk.

FIG. 15 is a perspective view of the spline disk and second pulley assembly.

FIG. 16 is a perspective view of a lower leg support link.

Fig. 17 is a schematic view of the operation of the power generation mechanism during a gait cycle.

Sequence numbers in the upper figure: the ankle rope comprises a knee rope 1, an ankle rope 2, a power generation mechanism 3, a first input shaft 4, a first input gear 5, a ratchet-pawl mechanism 6, a ratchet 61, a pawl 62, a compression torsion spring 63, a shell 64, a first pulley 7, a first torsion spring 8, an inner ring 81, an outer ring 82, a flexible body 83, an outer ring buckle 84, an inner ring buckle 85, a second input shaft 9, a second input gear 10, a one-way transmission mechanism 11, a toothed disc 111, a toothed disc 112, a second pulley 12, a second torsion spring 13, a linear compression spring 14, a first transmission shaft 15, a transition gear 16, a driving gear 17, a second transmission shaft 18, a driven gear 19, a turbine 20, a worm 21, a coupler 22, a generator 23, a shell 24, a thigh support 25, a shank support 26, a shank support link 27 and an ankle link 28.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Referring to fig. 1, the power generation device based on the human knee joint and ankle joint driving includes a power generation mechanism 3, a knee rope 1, an ankle rope 2, a thigh support 25, a shank support 26, a shank support link 27, and an ankle link 28.

Referring to fig. 2 and 3, the power generation mechanism 3 includes a generator 23, a worm gear mechanism, a first input mechanism, a second input mechanism, and a transition transmission mechanism. The generator 23 is a brushless dc generator with a model of Maxon EC32 Flat. The transition gear train includes a pair of gears and a transition gear 16. The transition transmission mechanism is respectively connected with the first input mechanism and the second input mechanism in a transmission way, and the worm shaft of the worm gear mechanism is connected with the input shaft of the generator 23 through the coupler 22.

Referring to fig. 5 and 6, the first input mechanism includes the first input shaft 4, the first input gear 5, the ratchet-pawl mechanism 6, the first pulley 7, and the first torsion spring 8. The first input gear 5, the ratchet wheel 61 of the ratchet wheel and pawl mechanism 6, the first pulley 7 and the first torsion spring 8 are sequentially sleeved on the first input shaft 4.

The first torsion spring 8 includes an inner ring 81 and an outer ring 82 which are concentric, and eight flexible bodies 83 are disposed between the inner ring 81 and the outer ring 82. Each flexible body 83 is formed by connecting more than one S-bend in sequence. Referring to fig. 8a, outer ring buckles 84 are uniformly distributed on the outer ring 82 on one axial side surface of the first torsion spring 8; referring to fig. 8b, inner ring buckles 85 are uniformly distributed on the inner ring 81 on the other axial side surface of the first torsion spring 8. Referring to fig. 6, the first torsion spring 8 is fixedly connected to the housing 24 of the power generation mechanism 3 by an inner ring clip 85, and is fixedly connected to the axial end face of the adjacent first pulley 7 by an outer ring clip 84.

Referring to fig. 9 and 10, the second input mechanism includes a second input shaft 9, a second input gear 10, a one-way transmission mechanism 11, a second pulley 12, a linear compression spring 14, and a second torsion spring 13. Referring to fig. 11, the one-way transmission mechanism 11 includes a toothed disc 111 and a toothed disc 112. The second input gear 10, the toothed disc 111 and the toothed disc 112 of the one-way transmission mechanism 11, the second pulley 12, the linear compression spring 14 and the second torsion spring 13 are sequentially sleeved on the second input shaft 9.

Referring to fig. 11 and 15, the spline disk 112 is fixedly attached to one side end surface of the second pulley 12 in an embedded manner. Referring to fig. 13, four arc-shaped teeth are uniformly distributed on the axial end face of one side of the tooth-shaped disc 111; referring to fig. 14, the gullet disc 112 includes an outer ring, an inner ring, and a plurality of toothed blades uniformly connected between the outer ring and the inner ring; the arc teeth of the toothed disc 111 and the single toothed blade of the toothed slot disc 112 have the same structure; when the toothed disc 111 and the gullet disc 112 are engaged, the four arc teeth on the toothed disc 111 are just embedded into the corresponding toothed blades on the gullet disc 112, as shown in fig. 12. Referring to fig. 11, one end of the linear compression spring 14 is fixedly connected to the housing 24 of the power generation mechanism 3, and the other end is fixed to the other end face of the second pulley 12; the elastic force of the linear compression spring 14 presses the second pulley 12 to maintain the toothed disc 112 and the toothed disc 111 in a meshed state.

Realizing one-way transmission: when the gullet disk 112 rotates counterclockwise with the second pulley 12, the toothed blade of the gullet disk 112 pushes the toothed disk 111 to rotate counterclockwise, and when the gullet disk 112 rotates clockwise with the second pulley 12, the gullet disk 112 presses the toothed disk 111 to compress the linear compression spring 14, so that the gullet disk 112 slides relative to the toothed disk 111, and the toothed disk 111 is not driven to rotate clockwise.

Referring to fig. 4, the pair of gears of the transition gear is a driving gear 17 and a driven gear 19. The driven gear 19 and the worm gear 20 are coaxially and fixedly mounted on the second transmission shaft 18, and the driving gear 17 and the transition gear 16 are coaxially and fixedly mounted on the first transmission shaft 15. The transition gear 16 meshes with the first input gear 5 and the second input gear 10, respectively, see fig. 2.

Referring to fig. 7, the ratchet-pawl mechanism 6 includes a ratchet 61, a pair of pawls 62, a pair of compression torsion springs 63, and a housing 64. The housing 64 is a ring-shaped housing with a flange, one end of the compression torsion spring 63 is fixedly connected with the pawl 62, and the other end of the compression torsion spring 63 is fixedly connected with the inner wall of the housing 64.

The power generation mechanism 3 is connected to a lower leg support 26 by a lower leg support link 27, see fig. 16.

Referring to fig. 1, 2 and 3, one end of the knee rope 1 is fixedly connected to the thigh support 25, and the other end of the knee rope 1 is fixedly wound around the first pulley 7 of the first input mechanism.

Referring to fig. 2 and 3, one end of the ankle rope 2 is fixedly wound around the second pulley 12 of the second input mechanism, and the other end of the ankle rope 2 is fixedly connected to an ankle link 28, see fig. 1.

The working principle of the invention is explained in detail as follows:

(1) when a user wears the power generation device of the invention to normally walk, based on gait analysis, in a complete gait cycle, the beginning of the gait cycle when the heel is just landed is recorded as 0%, the beginning of the gait cycle when the toe is separated from the ground is recorded as 60%, and 100% corresponds to the beginning of the next gait cycle.

As shown in fig. 17 (a), when the heel is landed, the knee joint is in an extension stage, and the first torsion spring 8 is in a torsion state and stores elastic potential energy, so that tension exists in the knee rope 1; the second torsion spring 13 and the ankle cord 2 are in a free state. In 0% -10% of gait cycle, the knee joint generates slight flexion movement, the knee rope 1 is loosened, partial elastic potential energy in the first torsion spring 8 is released to drive the first pulley 7 to rotate, the ratchet-pawl mechanism 6 is in a separated state in the rotating direction, so that the rotating movement is not transmitted to the transition transmission mechanism and the second input mechanism, and the generator 23 does not generate electricity; at the same time, the ankle joint makes a plantarflexion movement, the ankle cord 2 is further loosened, and the generator 23 does not generate electric power. As shown in fig. 17 (b), in 10% to 50% of the gait cycle, the knee joint is in the fully extended state, the knee rope 1 is stretched to the maximum extension, the knee rope 1 drives the outer ring 82 of the first torsion spring 8 to rotate through the first pulley 7, the rotation angle of the first torsion spring 8 is maximized, and the stored elastic potential energy is maximized, in this rotation direction, the ratchet-pawl mechanism 6 is in the locked state, so the knee rope 1 drives the generator 23 to generate electricity through the first input mechanism, the transition transmission mechanism and the worm gear mechanism; meanwhile, the ankle joint generates dorsiflexion motion, the loose ankle rope 2 is gradually tensioned when the gait cycle is 30 percent, the ankle joint continuously generates dorsiflexion motion in 30 to 50 percent of the gait cycle, the ankle rope 2 is stretched to drive the second pulley 12 to rotate, the second pulley 12 drives the outer ring of the second torsion spring 13 to rotate to store elastic potential energy, and in the rotating direction, the one-way transmission mechanism 11 is in a locking state, so that the ankle rope 2 drives the generator 23 to rotate through the second input mechanism, the transition transmission mechanism and the worm gear mechanism to realize power generation; in the process, the rotation directions of the first input mechanism and the second input mechanism input to the transition transmission mechanism are consistent, that is, the rotation directions of the first input mechanism and the second input mechanism input to the generator 23 are consistent, so that the generator 23 can realize the function of unidirectional power generation. When the first input gear 5 and the second input gear 10 are the prime movers of the first input mechanism and the second input mechanism, respectively, the ratchet-pawl mechanism 6 and the one-way transmission mechanism 11 are both in a separated state, and the rotational motion is not applied to the knee rope 1 and the ankle rope 2 through the first pulley 7 and the second pulley 12, respectively, so that the motions of the knee joint and the ankle joint do not interfere with each other.

As shown in fig. 17 (c), in 50% -60% of the gait cycle, the ankle joint starts to do plantarflexion movement, the ankle rope 2 gradually loosens, the elastic potential energy stored in the second torsion spring 13 is released, the outer ring of the second torsion spring 13 drives the second pulley 12 to rotate to keep the ankle rope 2 in a tensioned state, and thus the ankle rope 2 applies torque to the ankle joint to assist the ankle joint to accelerate, and the metabolic consumption of the human body is reduced. In the rotational direction in which the ankle rope 2 is contracted by the second pulley 12, the spline disc 112 and the toothed disc 111 are in a separated state, so that the rotational motion is not transmitted to the transition transmission mechanism and the first input mechanism. In 60% -80% of gait cycle, the ankle joint generates dorsiflexion movement, and the work done by the ankle joint is positive work, so that the positive work needs to be filtered out and not collected; biomechanical analysis shows that the dorsiflexion of the ankle joint in the swinging stage can only reach about 3 degrees and is far smaller than the dorsiflexion angle of the ankle joint in the standing stage, so that the length of the ankle rope 2 can be adjusted in advance, the ankle rope 2 is still in a loose state and is filtered when the dorsiflexion angle of the ankle joint in the swinging stage reaches the maximum, and the human body metabolism consumption increased by collecting the positive work of the ankle joint is avoided. In 50% -80 of gait cycle, the knee joint makes flexion movement, the knee rope 1 gradually relaxes, the elastic potential energy stored in the first torsion spring 8 is released, the outer ring 82 of the first torsion spring 8 drives the first pulley 7 to rotate to keep the knee rope 1 in a tensioning state, and therefore the knee rope 1 applies torque to the knee joint to assist the knee joint to accelerate, and metabolism consumption of a human body is reduced. In the rotational direction of the first pulley 7 retracting the knee cord 1, the ratchet-pawl mechanism 6 is in a disengaged state, so that no rotational movement is transmitted to the transition transmission mechanism and the second input mechanism. Therefore, the elastic potential energy stored in the first torsion spring 8 and the second torsion spring 13 is used to assist the walking of the human body in 50% -80% of the gait cycle, thereby simultaneously realizing the functions of power generation and walking assistance.

As shown in (d) of fig. 17, in 80% -100% of the gait cycle, the knee joint performs an extension movement from the maximum flexion angle, the knee rope 1 is stretched to drive the first pulley 7 to rotate, the first pulley 7 drives the outer ring 82 of the first torsion spring 8 to rotate, and the collected knee joint negative work is converted into elastic potential energy to be stored in the first torsion spring 8. In the direction of stretching the knee rope 1, the ratchet-pawl mechanism 6 is in a locked state, and the rotating motion drives the generator 23 to generate electricity through the transition transmission mechanism and the worm gear mechanism. In the process, the transition gear 16 drives the second input gear 10 to rotate, at this time, the second input gear 10 is a prime mover of the second input mechanism, so that the one-way transmission mechanism 11 of the second input mechanism is in a separated state, the rotation motion cannot act on the ankle rope 2 through the second pulley 12, and the ankle joint is in a free-moving state. As in fig. 17 (e), one gait cycle is completed and the next gait cycle is started.

In each next gait cycle, the above implementation process is continuously circulated.

It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included within the scope of the present invention.

Claims

1. Power generation facility based on human knee joint and ankle joint drive, its characterized in that: comprises a power generation mechanism (3), a knee rope (1), an ankle rope (2), a thigh support (25), a shank support (26), a shank support connecting rod (27) and an ankle connecting rod (28);

the power generation mechanism (3) comprises a power generator (23), a worm and gear mechanism, a first input mechanism, a second input mechanism and a transition transmission mechanism; the transition transmission mechanism comprises a pair of gears and a transition gear (16), the transition transmission mechanism is respectively connected with the first input mechanism and the second input mechanism in a transmission way, and a worm shaft of the worm gear mechanism is connected with an input shaft of a generator (23) through a coupler (22);

the first input mechanism of the power generation mechanism (3) comprises a first input shaft (4), a first input gear (5), a ratchet wheel and pawl mechanism (6), a first pulley (7) and a first torsion spring (8); the first input gear (5), the ratchet wheel (61) of the ratchet wheel and pawl mechanism (6), the first pulley (7) and the first torsion spring (8) are sequentially sleeved on the first input shaft (4);

the second input mechanism comprises a second input shaft (9), a second input gear (10), a one-way transmission mechanism (11), a second pulley (12), a linear compression spring 14 and a second torsion spring (13), and the one-way transmission mechanism (11) comprises a toothed disc (111) and a toothed disc (112); the second input gear (10), the toothed disc (111) and the toothed disc (112) of the one-way transmission mechanism (11), the second pulley (12), the linear compression spring (14) and the inner ring of the second torsion spring (13) are sequentially sleeved on the second input shaft (9);

a pair of gears of the transition transmission mechanism is a driving gear (17) and a driven gear (19); the driven gear (19) and the worm gear (20) are coaxially and fixedly arranged on the second transmission shaft (18), and the driving gear (17) and the transition gear (16) are coaxially and fixedly arranged on the first transmission shaft (15); the transition gear (16) is respectively meshed with the first input gear (5) and the second input gear (10);

the ratchet wheel and pawl mechanism (6) comprises a ratchet wheel (61), a pair of pawls (62), a pair of compression torsion springs (63) and a shell (64); the shell (64) is an annular shell with a flanging, the axial side face of the shell (64) is fixedly connected with the axial end face of the adjacent first pulley (7), the pair of pawls (62) are symmetrically and movably arranged in the shell (64), one end of the compression torsion spring (63) is fixedly connected with the pawls (62), and the other end of the compression torsion spring (63) is fixedly connected with the inner wall of the shell (64);

the first torsion spring (8) comprises an inner ring (81) and an outer ring (82) which are concentric, and eight flexible bodies (83) are uniformly distributed between the inner ring (81) and the outer ring (82); outer ring buckles (84) are uniformly distributed on an outer ring (82) on one axial side surface of the first torsion spring (8), and inner ring buckles (85) are uniformly distributed on an inner ring (81) on the other axial side surface of the first torsion spring (8); the first torsion spring (8) is fixedly connected with a shell (24) of the power generation mechanism (3) through an inner ring buckle (85) and fixedly connected with the axial end face of the adjacent first pulley (7) through an outer ring buckle (84);

each flexible body (83) is formed by connecting more than one S-shaped bend in sequence;

the toothed groove disc (112) is fixedly connected to the end face of one side of the second pulley (12) in an embedded mode; four arc-shaped teeth are uniformly distributed on the axial end face of one side of the toothed disc (111), the toothed disc (112) comprises an outer ring, an inner ring and a plurality of toothed blades, and the toothed blades are uniformly distributed and connected between the outer ring and the inner ring; the arc-shaped teeth on the toothed disc (111) are the same as the single toothed blade structure of the toothed slot disc (112); when the tooth-shaped disc (111) is meshed with the tooth-shaped disc (112), four arc-shaped teeth on the tooth-shaped disc (111) are just embedded into corresponding tooth-shaped blades on the tooth-shaped disc (112); one end of the linear compression spring (14) is fixedly connected with a shell (24) of the power generation mechanism (3), and the other end of the linear compression spring is fixed on the other end face of the second pulley (12); the elastic force of the linear compression spring (14) extrudes the second pulley (12) to enable the toothed disc (112) and the toothed disc (111) to keep a meshed state;

the power generation mechanism (3) is connected with a lower leg support (26) through a lower leg support connecting rod (27);

one end of the knee rope (1) is fixedly connected with a thigh support (25), and the other end of the knee rope (1) is fixedly wound on a first pulley (7) of the first input mechanism;

one end of the ankle rope (2) is fixedly wound on a second pulley (12) of the second input mechanism, and the other end of the ankle rope (2) is fixedly connected with an ankle connecting rod (28);

when in use, the thigh support (25) is fixed on the thigh of a human body, the shank support (26) is fixed on the shank of the human body, and the ankle connecting rod (28) is fixed on the heel of the foot of the human body.